1. Field of the Invention
This invention relates to a small reciprocating pump. In particular, it relates to a pump which is suitable for installation in a refrigerant device for an air conditioner for compressing a refrigerant such as Freon.
2. Description of the Prior Art
A known prior art pump has a large clearance volume when compared with its stroke volume, whether it may be of the plunger or piston type. Moreover, the temperature of its compression chamber is likely to be elevated owing to the influence of its environment. A vaporized refrigerant is therefore not fully liquified in such a system. Thus, such a pump lacks stability in operation.
This invention is concerned with specifically a pump for compressing a refrigerant. It is basically equal in construction to a reciprocating pump employed most commonly in the art. While a known pump for compressing a refrigerant discharges in the form of a vapor-liquid mixture, however, this invention is directed to a pump of the type which discharges a refrigerant in a fully liquefied form. No known reciprocating pump can liquefy a refrigerant completely. The known plunger pump is disclosed, for example, in U.S. Pat. No. 3,538,961, and a special pump is disclosed in Japanese Patent Publication No. 27366/77. None of these known pumps has been put to mass production and practical use, since they cannot liquefy a refrigerant completely and are too complex in construction.